The equipment may be placed on the dashboard, but often at a location that is found to be too far away from the driver for the driver to be able to reach it easily without interfering with driving. That is why the equipment is associated with a remote control for facilitating access to the commands of the basic functions of the equipment. The equipment may also be placed in a location that is normally inaccessible to the driver, for example in the glove box of the vehicle.
For equipment that is “retrofitted” to a vehicle, the use of a wireless remote control that communicates with the equipment by means of radio-frequency (RF) waves is found to be particularly convenient to install and to use.
The wireless remote control can be held in the hand or else it may be fastened to a support that is stuck on the dashboard within reach of the driver. It may also be mounted on the steering wheel of the vehicle, e.g. as described in U.S. Pat. No. 7,456,777 B2.
The remote control does not require a wire connecting it to the equipment, and the user can place the remote control support very simply at a desired location, e.g. on the dashboard, by means of an adhesive and without any need to lay wiring with the wires running behind the dashboard and without any other technical constraints for installation. The remote control may also be used while held in the hand, in particular by a passenger seeking to use the equipment.
Nevertheless, fully independent wireless use presents the drawback of needing to have recourse to a power supply battery, with it being necessary to husband its lifetime because of its small capacity due to its small size (a “button” battery). As a result, it is not possible to provide permanent backlighting of the keys on a wireless remote control, which is a drawback at night since it is not possible to see the location of the remote control and its keys in the dark. Finally, if the battery is exhausted, it becomes impossible to use the equipment until the battery has been changed, which assumes that a spare battery is always available if it is desired for the equipment to be usable under all circumstances.